I was re-reading Lovecraft's THE WHISPERER IN DARKNESS and came across one of those passages that effectively serve as info dumps of the Mythos.
In the story, Vermont farmer Henry Akeley, who has first-hand experience with the Mythos, tells what he knows in a letter to Miskatonic professor Albert Wilmarth, who knows a good deal about such things second hand, from reading the books there in his university's library. Here's how Lovecraft's Wilmarth describes the exchange:
. . . a terrible cosmic narrative derived from the application of profound and varied scholarship . . . I found myself faced by names and terms that I had heard elsewhere in the most hideous of connections—Yuggoth, Great Cthulhu, Tsthoggua, Yog-Sothoth, R'lyeh, Nyarlathotep, Azathoth, Hastur, Yian, Leng, the Lake of Hali, Bethmoora, the Yellow Sign, L'mur-Kathulos, Bran, and the Magnum Innominandum . . . worlds of elder, outer entity at which the crazed author of the Necronomicon had only guessed in the vaguest way
(THE DUNWICH HORROR AND OTHERS p. 227)
I'd always thought of THE NECRONOMICON more as a grimoire than anything else--that being the use Wilbur Whateley puts it to in THE DUNWICH HORROR. But Wilmarth's description makes me wonder: what if THE NECRONOMICON were more like a collection of stories (think Ovid)? Most of the items in Wilmarth & Akeley's list have a story devoted to it, either by Lovecraft himself, or one of his friends and correspondents, or one of the writers of a previous generation from which HPL directly borrowed. What if we were to think of THE NECRONOMICON as a compilation of stories? Thus WHISPERER is the Yuggoth tale; CALL OF CTHULHU the story about Great Cthulhu and Rl'yeh; DUNWICH HORROR the tale where we learn about Yog-Sothoth; DREAM-QUEST the Nyarlathotep tale, and so forth. The middle part of the list allude to works by writers of the generation before Lovecraft, still alive and writing when Lovecraft was beginning his career: Bierce (Lake of Hali), Chambers (The Yellow Sign), and Dunsany (Bethmoora).
The analogy's not perfect --so far as I know there's no story about Yian, or some of the other more obscure items towards the end of the list. And the chronology's all off. But it's still striking, and Lovecraft deliberately left some things vague so he cd add to or adjust elements in the Mythos as needed for later stories. The Mythos was open-ended, and to some degree self-contradictory, like a real mythology.
For instance, in what way might Bethmoora come up in Akeley and Wilmarth's pooling of their knowledge? The best way for them to have learned the legend of what happened to this city is to hear it from a deranged cultist (Akeley) or read it in an Arkham book (Wilmarth). And that legend would closely correspond to the actual tale written, and published, by Dunsany (in A DREAMER'S TALES, 1910). For another example, if a fictional character reading about The Yellow Sign in the NECRONOMICON is learning pretty much the same story as a real-world reader reading Chamber's tale "The Yellow Sign", then the closest approach we can make to replicating the contents of THE NECRONOMICON is to compile an anthology of the relevant tales.
At any rate, that the idea I'm currently playing around with, musing over and seeing where it goes.
My friend Charles N. (hi, Charles) points out in an email that Snorri's PROSE EDDA sounds a better match for Alhazred's NECRONOMICON: cryptic poems with explanatory background added. He further suggests that
many, if not most, of the 'authentic' quotations from the Necronomicon
were in fact poetry in the original Arabic, but only survived as prose
in the successive Greek and Latin translations.
We do know there's at least one "chant" in the book, referred to as such by Wizard Whateley (in THE DUNWICH HORROR) as lacking in his damaged copy.